mirror of https://git.tukaani.org/xz.git
169 lines
3.4 KiB
Groff
169 lines
3.4 KiB
Groff
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.\"
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.\" Author: Lasse Collin
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.\"
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.\" This file has been put into the public domain.
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.\" You can do whatever you want with this file.
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.\"
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.TH XZDEC 1 "2009-06-04" "Tukaani" "XZ Utils"
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.SH NAME
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xzdec, lzmadec \- Small .xz and .lzma decompressors
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.SH SYNOPSIS
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.B xzdec
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.RI [ option ]...
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.RI [ file ]...
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.br
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.B lzmadec
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.RI [ option ]...
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.RI [ file ]...
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.SH DESCRIPTION
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.B xzdec
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is a liblzma-based decompression-only tool for
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.B .xz
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(and only
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.BR .xz )
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files.
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.B xzdec
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is intended to work as a drop-in replacement for
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.BR xz (1)
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in the most common situations where a script has been written to use
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.B "xz \-\-decompress \-\-stdout"
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(and possibly a few other commonly used options) to decompress
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.B .xz
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files.
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.B lzmadec
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is identical to
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.B xzdec
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except that
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.B lzmadec
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supports
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.B .lzma
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files instead of
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.B .xz
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files.
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.PP
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To reduce the size of the executable,
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.B xzdec
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doesn't support multithreading or localization, and doesn't read options from
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.B XZ_OPT
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environment variable.
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.B xzdec
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doesn't support displaying intermediate progress information: sending
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.B SIGINFO
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to
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.B xzdec
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does nothing, but sending
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.B SIGUSR1
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terminates the process instead of displaying progress information.
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.SH OPTIONS
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.TP
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.BR \-d ", " \-\-decompress ", " \-\-uncompress
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Ignored for
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.BR xz (1)
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compatibility.
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.B xzdec
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supports only decompression.
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.TP
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.BR \-k ", " \-\-keep
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Ignored for
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.BR xz (1)
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compatibility.
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.B xzdec
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never creates or removes any files.
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.TP
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.BR \-c ", " \-\-stdout ", " \-\-to-stdout
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Ignored for
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.BR xz (1)
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compatibility.
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.B xzdec
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always writes the decompressed data to standard output.
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.TP
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\fB\-M\fR \fIlimit\fR, \fB\-\-memory=\fIlimit
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Set the memory usage
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.IR limit .
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If this option is specified multiple times, the last one takes effect. The
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.I limit
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can be specified in multiple ways:
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.RS
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.IP \(bu 3
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The
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.I limit
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can be an absolute value in bytes. Using an integer suffix like
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.B MiB
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can be useful. Example:
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.B "\-\-memory=80MiB"
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.IP \(bu 3
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The
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.I limit
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can be specified as a percentage of physical RAM. Example:
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.B "\-\-memory=70%"
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.IP \(bu 3
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The
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.I limit
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can be reset back to its default value (currently 40 % of physical RAM)
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by setting it to
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.BR 0 .
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.IP \(bu 3
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The memory usage limiting can be effectively disabled by setting
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.I limit
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to
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.BR max .
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This isn't recommended. It's usually better to use, for example,
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.BR \-\-memory=90% .
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.RE
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.IP
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The current
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.I limit
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can be seen near the bottom of the output of the
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.B \-\-help
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option.
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.TP
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.BR \-q ", " \-\-quiet
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Specifying this once does nothing since
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.B xzdec
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never displays any warnings or notices.
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Specify this twice to suppress errors.
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.TP
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.BR \-Q ", " \-\-no-warn
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Ignored for
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.BR xz (1)
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compatibility.
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.B xzdec
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never uses the exit status
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.BR "2" .
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.TP
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.BR \-h ", " \-\-help
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Display a help message and exit successfully.
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.TP
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.BR \-V ", " \-\-version
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Display the version number of
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.B xzdec
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and liblzma.
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.SH "EXIT STATUS"
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.TP
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.B 0
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All was good.
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.TP
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.B 1
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An error occurred.
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.PP
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.B xzdec
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doesn't have any warning messages like
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.BR xz (1)
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has, thus the exit status
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.B 2
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is not used by
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.BR xzdec .
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.SH NOTES
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.B xzdec
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and
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.B lzmadec
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are not really that small. The size can be reduced further by dropping
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features from liblzma at compile time, but that shouldn't usually be done
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for executables distributed in typical non-embedded operating system
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distributions. If you need a truly small
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.B .xz
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decompressor, consider using XZ Embedded.
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.\" TODO: Provide URL to XZ Embedded.
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.SH "SEE ALSO"
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.BR xz (1)
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